Bees of Canada Logo

Xenoglossa pruinosa (Say, 1837)


Scientific Name: Xenoglossa pruinosa (Say, 1837)

Common Name: Hoary Squash Bee


Macrocera pruinosa Say, 1837: 405 [♂, ♀].

     Syntypes ♂, ♀. USA “United States” [presumably destroyed].

Xenoglossa spriuna Howard, 1901: Pl. vii, Fig. 2 [♂]. Synonymy by Viereck (1916: 733).

     Holotype ♂. USA, Mississippi, Utica, August [no year provided] [USNM no. 23989].

Xenoglossa angelica Cockerell, 1902: 103 [♂, ♀]. Synonymy by Hurd and Linsley (1964: 452).

     Syntypes ♂, ♀. USA, California, Los Angeles, 22 July [1901], 8♂, 3♀, by T.D.A. Cockerell, on Curcurbita foetidissima; Los Angeles Co., County Farm, 15 July [1901], by T.D.A. Cockerell, on Ipomaea. [male co-type at SEMKU no. 4435].

Xenoglossa (Peponapis) howardi Cockerell, 1918: 420 [♂, ♀]. Synonymy by Hurd and Linsley (1966: 845),

     Holotype ♂. MEX, Federal District, by J.R. Inda [USNM no. 23173].

Xenoglossa pruinosa var. lutzi Cockerell, 1923 : 420 [♀, ♂]. Synonymy of Peponapis pruinosa pruinosa (Say, 1837) by Michener (1951: 1221).

     Syntypes ♀, ♂. USA, Colorado, Grand Junction, approx. 4,500 ft, 2♀, 25♂; 3 August 3, 1920, by Lutz (Lutz 4758 and 4758 B) [AMNH].

Macrocera prinosa Michener, 1951: 1221. Lapsus for Macrocera pruinosa Say, 1837.


Taxonomic notes: Patton (1879: 473) was the first to place this species in the genus Xenoglossa Smith, 1854, though it has most frequently been referred to as a member of the genus Peponapis Robertson, 1902 (and is the type species) (Michener 1951; Hurd and Linsley 1964, 1966; Mitchell 1962; Hurd et al. 1971, 1974), though recent phylogenetic analyses have treated Peponapis as a subgenus of Eucera Scopoli, 1770 (Dorchin et al. 2018a, 2018b), or returned it to Xenoglossa, also as a subgenus (Viereck 1916; Cockerell 1932; Freitas et al. 2023).

Viereck (1916: 733) noted that the name Xenoglossa spriuna Howard, 1901, only appearing on Plate VII, Fig. 2 of The Insect Book by Howard (1901), probably represented a lapsus of X. pruinosa (Say, 1837) and recorded it as a synonym. However, preceeding the mention of Xenoglossa spriuna in the first edition, Howard (1901, Plate III, Fig. 1) also recorded Xenoglossa pruinosa; Hurd and Linsley (1964: 450) indicated that both figures represented males, which would support that Howard (1901) treated these as separate species. Support for this comes from the existence of a holotype male of Xenoglossa spriuna at the USNM, the specimen matching the photo used in that work (Howard 1901). However, in the second edition (i.e., Howard 1905) both Plate III, Fig. 1 and Plate VII, Fig. 2) use the name Xenoglossa pruinosa suggesting that either Howard became aware of the lapsus, and/or that the specimen featured in Plate III was the female, and Plate VII the male.

Cockerell (1902: 103) indicated that his Xenoglossa angelica Cockerell, 1902 was similar to the eastern X. pruinosa, differening by the velvety pubescence of the abdomen being golden, not silvery-white. Hurd and Linsley (1964: 453) were not able to locate the type material of X. angelica, though a male co-type was recorded from the Snow Entomological Collection at University of Kansas [SEMKU no. 4435] (LaBerge 1956: 508).

Cockerell (1918: 421) placed Xenoglossa howardi Cockerell, 1918 in the subgenus Peponapis Robertson, 1902, though indicated that it differed from the type species (i.e., Macrocera pruinosa Say, 1837) by the entirely black clypeus in the male, and reduction of pale hair on the metasoma of the female; this seems to be variation. He later described Xenoglossa pruinosa var. lutzi Cockerell, 1923 as a variety, noting that 1 of the 25 males in the type series lacked a clypeal maculation, though the females had the apical segments of the abdomen reddened with reddish pubescence. Hurd and Linsley (1966: 845) commented further on the variation in this species, suggesting it was clinal in cause.

DNA Barcode Index Number (BIN): BOLD:AAE0476

Biology: Mathewson (1968) and Hurd et al. (1974) provide a detailed account of the biology of this species. 

Distribution in Canada: Kevan et al. 1989 [ON]; Payette and Payette 2003 [QC]; Willis Chan and Raine 2021 [ON]; Sharkey 2022 [ON]; Stegman 2022 [ON]; Rondeau and Raine 2023 [ON].


Cockerell TDA (1932) Names applied to the eucerine bees of North America. Proceedings of the United States National Museum 43(1932): 261-273.

Willis Chan DS, Raine NE (2021) Phenological synchrony between the hoary squash bee (Eucera pruinosa) and cultivated acorn squash (Cucurbita pepo) flowering is imperfect at a northern site. Current Research in Insect Science 1: 1-8.

Rondeau S, Raine NE (2024) Single and combined exposure to ‘bee safe’ pesticides alter behaviour and offspring production in a ground-nesting solitary bee (Xenoglossa pruinose). Proceedings of the Royal Society B 291: 20232939.

Payette A, Payette M (2003) Première mention de l’abeille Peponapis pruinosa (Say) (Hymenoptera : Apidae) pour le Québec. Fabreries 28(1) : 37-47.

Sociality: Solitary
Nesting: Ground
Pollen Specialization: Narrow Oligolecty
Wintering Stage: Mature Larva

Crop Preference: Cucurbita pepo
Non Crop Preference: Not Available

Distribution: Ontario, Quebec
Ecozone: Mixwood Plains